oufan2929

Well, I've been told two different things by two different VERY notable shops on break-in procedure. One is telling me to drive it at least 1,000miles to make sure to go through different heat cycles and seat everything properly. The other shop told me to drive 10-15 miles and then put the car on the dyno and flog the crap out of it to break it in correctly. What do you guys think? Thanks--Andy

blkZ28spt

What have you had done? Valvesprings should get a few heat cycles on them to be safe......

30th droptop

iTrader: (-1)

I've always been a little nervous about getting on a motor too quickly. The rings usually seat in the first 200-300 miles, and that's the main break-in issue with these motors. Since we've got roller cams, there's not too much of an issue of cam break-in.

But like I said, I'm always a bit nervous about getting on a motor too quickly. I look at the break-in period as also a "shakedown" period. Any issues with cooling, lubrication, loose bolts, etc. will usually show up in the first 1000 miles or so. And I'd hate to find out I had a loose rod bolt while the engine was over 6,000 rpm!

technical

Break it in like you plan on driving it. I would hold off any 1/4 or dyno time for 100 miles or so. Change the oil before the first dyno/track and all will be good.

oufan2929

A complete top to bottom custom built 8.8-1CR 408 and it's going in the car very soon

blkZ28spt

Sounds fun. I would never feel safe getting on a fresh, 15 mile motor.

777

iTrader: (21)

how did your engine let go...

87calais

The Machine shop I took my stuff to said that I should just keep it at 1500Rpm for 20 minutes or so to seat the rings...... Betcha I give it a couple days driving before I start to flog on it. Then it's hello revlimiter.

Last Yellow Bird

iTrader: (1)

Just had a cam, springs, rods swap done by Speed Inc. They dyno tune it when finished, so that have to rev it before lots of miles. When I picked it up, I asked what kind of break-in was required, and they told me none, to just go enjoy it. I would usually be cautious of getting on a motor to soon after this kind of work, but I got to thinking, we all have work done and dyno tuned immediately, so that must be okay. Kind of a contradition. So I decided to go with what the pros told me. I enjoyed it alot, right down Albion street in front of the shop!

Ryan1985

one heat cycle then give it hell. If its gonna let go its gonna let go.

Taspeed

iTrader: (1)

I have always started them and let em run for around 15 to 20 minutes. Let them cool for about 30 minutes and drive it around town for a bit. I put at LEAST 500 miles on them before I hammer on it. Those rings still have to seat, and even at 500 they really have barely begun to seat. Run em hard early on and most can expect oil usage problems later on.

VSGLS1

iTrader: (8)

How much oil usage during breakin? How long before the rings finally seat, even if it was flogged on a dyno after 500 miles? I think I am going to just let it warm up for 15-20 minutes, check everything then flog it on the nearest open road.

GuitsBoy

iTrader: (4)

I think what the second shop is referring to is a relatively new idea in engine breakin. Basically the idea is that you only have a short window in the very beginning to allow the rings to wear in under heavy load. Supposedly the still rough hone pattern and the added heat and friction of driving it hard when brand new is supposed to produce very tight ring to wall seals. I wish i had saved the link. Ill post back if i can find it again.

cyphur

iTrader: (10)

I think I know what link you're talking about, some guy that has a website that thinks he created the procedure for rough break-ins. I thought I had it bookmarked but no such luck.

Viper

iTrader: (6)

I've got it here:

http://www.mototuneusa.com/break_in_secrets.htm



And FWIW, I'm in the same boat; new motor. Thought about breaking it in on the dyno. Basically assembling the car in the garage, one heat cycle, then flat bed the car to the dyno ( it's farther than 20-30 miles ).

GuitsBoy

iTrader: (4)

Thanks for backing me up, C_T. Viper, thats the link. I dont know how I feel about the method, but its difinately an interesting read. Wish there were some more info / studies on this.

-T

Viper

iTrader: (6)

I've been trying to find a good answer as well since last fall when my motor died and I knew I was getting a new one. I want to do it right, and so far 2 engine builders have given me both ideas ( same as in this post ).

Either

Drive it like you stole it from day one

or

Baby it for a couple hundred miles.


Of course logically it makes sense that if it's going to break, does it matter if it's at 20 miles or 2000?

Blue Hawk

The key to properly seat the rings is to keep the engine under load in acceleration and deceleration.

This is the way I did my break-in. I drove the car as much as i could on the highway (going nowhere) shifting constantly my speed between 40 and 70 mph. In 4th or 5th gear, from 40 mph I gradually applied the throttle to 3/4. At 70 mph I let off the throttle and let the engine break the car to 40 mph. Again and again...

I did this for the first 800 miles. I did applied WOT a few times, but never hammered the pedal or revved over 3500 rpm.

I did this with success to 4 engines. Never had a problem after that.

cyphur

iTrader: (10)

werd.

i think as long as your valvesprings are heat-cycled properly it'd be good to go. it makes sense using higher cylinder pressue to force the rings to seat early. the rings don't have to heat cycle either way.

Another_User

Exactly how I do it. But I would hold off a hair longer on the dyno. I always flog my cars on the street (within the recommended limits, some cars you are only supposed to rev so high until they are done breaking in).